Testing refrigerant fluids



Patented idling 24, 15923..

dl'ATES PAT VJILLLAM C. DEVER, OF, DETRCiIT, MICHIGAN, ASSIGNOR TO KELVJCNATOTIBI GOPJPORA- TION, F DETROIT, MICHIGAN, A CORPORATION OF MICHIGAN.

TESTING REFRIGERANT IFIJU'ZIIDFi.

firiginal application filed August 1, 1925, serial No. 47,507 Divided and this application filed April 22,

' 1926. Serial No. 103,889.

successful as a refrigerant only when substantially free from moisture inasmuch as any appneciable quantity of dissolved water "reacts upon the sulphur dioxide with the production of corrosive fluid, while any presence of atmospheric oxygen in addition to the moisture enhances the corrosive effect with the result that pistons bind, valves stick, pipes become corroded, and lubrieation is injured; while if the refrigerant be anhydrous it exhibits no injurious eitcct upon the mechanism. 1. have discovered that the maximum permissible water content is about .0670 and the herein described improvements in apparatus and method have been devised for the purpose of facilitating analysis by comparatively untra ned men and equally available to themakcr and the user of sulphurdioxide. \Vater in other refrigerants is sometimes objectionable because of freezing.

In the drawings accompanyingand torming a part of this application Fig. 1 illustratcs'a side elevation of a simplified apparatus for the performance of my testing process; Fig. 2 is a sectional view corresaonding to the lines 2-2 of Fig. 1; and ig. 3 is a rear elevation of the apparatus shown in Fig. 1.

1 denotes a glass vessel having a cylindrical mouth 2 adapted for the reception of a rubber stopper 3 or other t ghtiy fittings, removable closure, and having its lower end reduced in diameter to form a prolong 4: which in turn is again reduced to form a second prolong 5, the latter closed. by an integ'ral bottom 6. In the form shown the body of the vessel thus produced has :1 capacity of between 200 andBOO cubic centimeters, the prolongi a capacity of approximately 1 cubic centimeter and the rolong 5 a capaeit timeter. I have tound the following approxinnate dimensions very convenient; diameter of body 1 inch, length of up or cylindrical portion t1. inches; diameter 0 first prolong of approximately on ie cen- 5 inch; length of first prolong 1% inch;

diameter of second prolong inch; length of second prolong inch; total length oi tube inches.

This tube is accurately graduated on the lower prolong to Tip of a cubic centimeter. Thelarger prolong isgraduated to cubic centimeter; and the body of the tube is graduated at say 100 c. c. with a suitable level indication such as shown at 6. It need not be at 100 c. c. for both it and the other graduations may be empirical if desired; in fact this is a very desirable arrangement. e

This stopper is here shown as coupled by means of a glass tube 10 to a rubber connection 11 which leads to some point of con-' vemcnt discharge for the evolved gas. The

end of the tube'32 is here partly closed to reduce inflow of air which might bring mois- .ture.

The apparatus'is prepared for the test as follows: i

in order to conduct a test a fresh representative sample of the retrigerant liquid is introduced into the clean and dry tube 1,

this tube being preferably at about room temperature filling same to the mark 6. It is then quickly closed by the stopper 3 (in order to minimize the opportunity of absorbing moisture from the atmosphere) and the apparatus connected as shown in the drawing and the volatile fluid allowed to evaporate naturally at room temperature until as much of the same has disappeared as will pass off under these conditions. This ordinarily requires several hours and it is best to distil itslowly since less water is evaporated under such condition. The tube 1 is allowed to assume room ten'iperature" (the evaporation .of the volatile liquid al- Wayscools it much below this point), and

the amount of residuum noted. The fact of the tubes assuming room temperature is the indication that only wateror other non-' volatile liquid remains.

In case the amount of liquid remaining in the bottom of the tube issutticient to fill the prolpngs 4i and 5 it is obvious at a glance that the liquid is unduly impure for retrigcrating purposes. Ordinarily v the residue should not more than halt till the smaller prolong and the same is reduced to percenta e by application of the formula Emv fldd, wherein Papercentsge of water by weight and 1.49 isthe specific gravity of liquid sulphur dioxide, assuming that to be the substance under test. Thus in case the tube shows a residue of .03 c. c. the percentage of water corresponding thereto'is Did/1.492.020.

Part of the water content also distills away with the volatile liquid but this amount bears substantially a constant proportion to that left behind, in case the evaporation is conducted gradually and at moderate temperatures. By comparing theresults exhibited by this apparatus with a complete chemical analysis of companion samples a correction factor is obtained which can be applied to the observed read ing with that particular liquid and a determination made within a sufiicicnt degree of accuracy for all practical purposes. Of course difierent liquids will require difi'er ent correction factors. Thus with sulphur dioxide the amount of water which distils over is generally about the same as that remaining behind, but with ammonia the ratio is very different. 7

It is also possible and is Within my invention to calibrate the prolongs of the tube 1 so as to exhibit directly the percentage of water present, although this means that the tube so calibrated can be used only for the one liquid for which it was designed. The calibration now takes care of the difierence in specific gravity as well as the amount of wa er distilling over. This means that the calibration is wholly empirical, each mark being evaluatedby a special analysis; and for this reason-the mark 6 need not designate any standard volume but .may be placed whenever convenient. 'This mode of procedure avoids all Wei of chemicals, and afio'r s a determination sufficiently exact for most purposes. It is important, however, in this "case, to force the refrigerant to evaporate at .a'uniform rate,

and to compel this I prefer'to enclose it in asuitable jacket which shall both hold it upright and regulate the rate of heat. absorption. Such a device is shown at 12, and here comprising a hollow wooden upright car ried by a base 13 and adapted to receive the tube 1. The upright has a slot or opening 14in front to permitinspection of the liquid level, and is formed at the back with windows 15 and 16 opposite the graduations to facilitate reading the same.

It will be obvious that many changes can be made within the scope of my invention wherefore I do not limit myself in any wise except as specifically recited in my several claims which I desire may be construed, each independently of limitations contained in other claims.

Having thus described my invention what I claim is:

L Apparatus for determining the percent hing, all liandlingrectly .thepercentage'of water by weight which is indicated by a corresponding residuum, said. graduations being adjusted to compensate for the amount of water vapor distilling oil? with the volatile component.

2. Apparatus for determining the percentage of water in liquid refrigerant media comprising a glass container having a liquid level line, a removable closure for the upper end of said container, and a reduced prolong at the lower end thereof, said prolong having graduations thereon which indicate directly the percentage of water by weight which is indicated by a'corresponding residuum, said graduations being adjusted to compensate for the amount of water vapor distilling off with the volatile component, and means for maintaining the distillation conditions approximately constant as regards the rate of access of heat to said tube.

3. Apparatus for determining .the percentage of water in liquid refrigerant comprising a glass container having a liquid level line, a removable closure for the upper end of said container, and a reduced prolong at the lower end thereof, saidprolong having graduations thereon which'indicate directly the percentage of water by weight which is indicated by a corresponding residuum, said graduations being adjusted to compensate for the amount of water vapor dication, and a partial closure for said container adapted to allow gas to escape while preventing air from entering.

5. Apparatus for determining approxi mately the percentageof water in liquid sulphur dioxide comprising a glass container of substantial size having a liquid level in- .dication thereon and also having at its lowest part a constricted-well graduated into volumes ranging from about one ten thousandth to about ue one thousandth of the volume indicated by said liquid level indication, a partial closure for said container adapted to allow gas to escape while preventing air from entering, and a shield for amie said container adapted to restrict the rate of heat absorption.

6. Apparatus for determining approxi niatelv the percentage of Water in liquid refrigerants comprising a glass container of substantial size having 1 liquid level indication thereon and also having at its lowest part a constricted Well graduated into volumes ranging from about one-ten thousandth to about one one thousandth of the volume indicated by said liquid ievel; indication, and a supporting device for said c0niainer adapted to restrict the rateof heat absorption Thereby.

1. Apparatus for determining approxii rnately the percentage of water in liquid rcfrigerants comprising a giass container of substantial size having a liguid level indication thereon and also having at its lowest 'part a constricted Well graduated into volumes ranging from about one ten thousandth to about one one thousandth of the volume indicated by said liquid level indication, and

a hollow wooden casing closely receiving said container and holding it upright, said casing having Windows revealing the. graduations and liquid level indications.

In testimony whereof I hereunto aflix my signature.

WILLIAM C. DEV-ER. 

